From owner-freebsd-hackers Wed Jul 7 19: 5:11 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from alpo.whistle.com (alpo.whistle.com [207.76.204.38]) by hub.freebsd.org (Postfix) with ESMTP id 69EFA14BCD; Wed, 7 Jul 1999 19:04:46 -0700 (PDT) (envelope-from julian@whistle.com) Received: from current1.whistle.com (current1.whistle.com [207.76.205.22]) by alpo.whistle.com (8.9.1a/8.9.1) with SMTP id TAA32439; Wed, 7 Jul 1999 19:04:27 -0700 (PDT) Date: Wed, 7 Jul 1999 19:04:26 -0700 (PDT) From: Julian Elischer To: Matthew Dillon Cc: Greg Lehey , Peter Jeremy , freebsd-current@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: Bursting at the seams (was: Heh heh, humorous lockup) In-Reply-To: <199907080137.SAA95818@apollo.backplane.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG we already use the gs register for SMP now.. what about the fs register? I vaguely remember that the different segments could be used to achieve this.... (%fs points to user space or something) julian On Wed, 7 Jul 1999, Matthew Dillon wrote: > :Why not put the kernel in a different address space? IIRC there's no > :absolute requirement for the kernel and userland to be in the same > :address space, and that way we would have 4 GB for each. > : > :Greg > > No, the syscall overhead is way too high if we have to mess with MMU > context. This would work fine on certain cpus with hardware PID support, > such as the MIPS, but the entire TLB is wiped when you change the mmu > context on an Intel cpu. > > -Matt > Matthew Dillon > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message